Bedtime Blues

Rapunzel doesn't sleep well at night.  She barely sleeps at all.  I'll go in and check on her at different times during the night and she's almost always laying there awake, scratching.  And the times when I check on her and she's actually asleep, she's still scratching.  We've tried so many different things to try to help her sleep.  She's been on numerous different antihistamines and meds (otc and rx) and nothing has helped.  They don't help with the itch and they don't help her to sleep.  We've moved her to her own room, with a humidifier, air purifier, nightlight, and music.  We keep her room cool at night and keep her skin covered with bandages and long sleeve cotton pajamas.  We have a bedtime routine that includes reading and snuggles.  Some nights I leave her alone, hoping she'll be able to sleep without my distraction.  Some nights I lay in bed with her hoping that me being present will help her sleep.  I let her sleep in on days when we don't have anywhere to be.  I wake her up early on days we do have somewhere to be. Nothing seems to help.  I'm kind of at my wit's end here.  I'm open to any and all suggestions anyone may have on ways to help her sleep.